This organization is formed to cooperate in research on malignant disease in children; specifically to study the factors which may cause or influence these diseases, and to develop, evaluate and improve methods of treatment. The primary objective of the cooperative group has been the evaluation of new biological and chemotherapeutic agents in the treatment of acute leukemia and solid tumors in childhood, and to find new and better ways of using the already known agents. It is also our objective to provide supportive care for these children with leukemia and solid tumors while they are on protcol studies and to evaluate the effect of this supportive care on their longevity and their well-being. This supportive care includes financial supportive care (domicillary care, travel assistance, out-patient costs, etc.), social service assistance, as well as medical supportive care. BIBLIOGRAPHIC REFERENCES: Sitarz, A.L., Albo, V.C., Movassaghi, N., Karon, M., Weiner, J., and Hammond, D.: Incidence of CNS Leukemia in Children with ALL and AUL receiving Cyclophosphamide or Dibromodulcitol for remission maintenance. AACR + ASCO Proc. 15:48, 1975 (abstract) Presented by Dr. Sitarz. Finklestein, J.Z., Albo, V.C., Ertel, I., Hammond, D.: 5-(3-3-Dimethyl-l-triazeno) imidazole-4-carboxamide (NSC-45388) in the Treatment of Solid Tumors in Children, Cancer Chemotherapy Reports Part 1, Vol. 59, No. 2, Mar/Apr. p 351, 1975.